1. Field of the Invention
The present invention relates to mobile terminals and methods of operation in which mobile terminal functions are initiated by soft keys during an inactive mode of a keypad thereof.
2. Description of the Prior Art
FIG. 1 shows prior art mobile terminal 1 of the Assignee used for cellular telecommunications which communicates via a wireless telecommunication network, e.g. a cellular network. However, the mobile terminal 1 could be used in a cordless network.
The keypad 2 has a first group of twelve keys 7, e.g., alphanumeric keys, by means of which the user can enter a telephone number, write a text message (SMS), write a name (associated with the phone number), etc. Each of the twelve alphanumeric keys 7 is provided with identifying numerals “0-9” or a “#” or “*”, respectively. In alpha mode, each key is associated with a number of letters and special signs are used in text editing.
The keypad 2 additionally comprises a second group of keys which are two soft keys 8, two call handling keys 9, and a navigation key 10. The two soft keys 8 operate in conjunction with the liquid crystal display 3 to display text which varies dependent upon the mode of operation and provides the user with the ability to select different programmed modes of operation provided by programming resident in the memory 17. Soft keys are not limited to the selection of a single dedicated terminal function. The illustrated soft keys 8 may have a functionality corresponding to the Assignee's models 2110™ and 8110™. At least one of the soft keys is defined as an operation key 8a having multiple functionality for handling access to a menu structure. The functionality of the operation key 8a depends on the present state of the phone. The operation key 8a is arranged to perform a group of predetermined actions associated with a state. The default function or the present function of the operation key 8a can be displayed in a predetermined area 21 of the display 3, as illustrated in FIGS. 3 and 5(a) and 5(b), just above the key 8a. 
The scroll key 10, which can also be called a navigation key, is an up/down key and is placed centrally on the front surface of the phone between the display 3 and the group of alphanumeric keys 7. The user controls the scroll key 10 by simply pressing the up/down key using his/her thumb which allows the user to scroll between a group of items in a menu provided in the user interface. Since many experienced phone users are used to one-hand control, it is a very good solution to place an input key, requiring precise motor movements. Thus, the user may place the phone in the hand between the finger tips and the palm of the hand. The thumb is thereby free for inputting information. The scroll key 10 can be a roller key (not shown), which is arranged to rotate in one or several directions. The roller key allows the user to roll the key to scroll between different items in a menu. The roller key 10 may be in accordance with the Assignee's U.S. patent application Ser. No. 08/923,696 which is incorporated herein by reference in its entirety.
Further, the scroll key 10 allows the user to scroll selectively between a group of items in a menu. This means that the user can select an item preceding or succeeding the item in the menu loop of the phone, while he/she can access a sub-menu loop under the item concerned in the menu loop by activation of the operation key 8a. 
In some states, such as entering a phone number on the alphanumeric keypad 7, the other soft key 8b can be defined as a clear key, which may be used for erasing the last entered digit or letter by brief depression on the clear key 8b. If the clear key 8b is depressed for a longer duration, the entire number or word is erased.
Although the functions of the mobile terminal 10 may be controlled by the operational key 8a, it sometimes can be expedient to use two or more operational soft keys in the second group of keys, which can be integrated into a touch-sensitive display (not shown) in a manner analogous to a screen of a personal digital assistant (PDA).
The two call handling keys 9 are used for establishing a call or a conference call, terminating a call or rejecting an incoming call.
FIG. 2 schematically shows a block diagram of major parts of the mobile terminal 1 of FIG. 1. These parts are conventional and are typically used in mobile terminals such as those in which the present invention may be practiced. The microphone 6 records the user's speech, and analog signals formed thereby are A/D converted in an A/D converter (not shown) before the speech is encoded in an audio part 14. The encoded speech signal is transferred to a controller which is a programmed microprocessor 18 that executes programming to control the mobile terminal 1 of FIG. 1. The processor 18 may execute diverse types of software to provide a wide variety of terminal functions during an active mode which are well known. The processor 18 also forms the interface to peripheral units, comprising a LCD driver 13 which drives the LCD display 3 of FIG. 1 to provide graphical displays to the user, RAM memory 17a and a Flash ROM memory 17b, a SIM card 16, and the keyboard 2 in the form, for example without limitation, of a keypad (as well as data, power supply, etc.). The processor 18 communicates with a transmitter/receiver 19, which sends/receives a request/response to/from one or several telecommunication networks. The audio part 14 speech-decodes the signal, which is transferred from the processor 18 to the speaker 5, via a D/A converter (not shown).
The processor 18 is connected to the user interface. The processor 18 monitors the activity in the mobile terminal 1 and controls the display 3 through display driver 13. The plurality of states which may be assumed by the mobile terminal 1 are displayed on display 3. The processor 18 detects the occurrence of a state changing event, and changes the state of mobile terminal 1. State changing events affect the functionality of the operation key 8a, and redefine it, in response to the preceding state and the nature of the detected state change event. Thus, a state change may also cause a change of the displayed text. A state changing event may be caused by the user when pressing the keypad, as shown in FIG. 1. This type of state changing events are called entry events or user events. Also, the network communicating with the phone may cause a state changing event. This type of event and other events beyond the user's control are called non user events. Non user events comprise status change during call set-up, change in battery voltage, change in antenna conditions, message on reception of SMS, etc.
In FIG. 3 a single display example is illustrated of the many mobile possible terminal functions which may be selected during the active mode of the keyboard by key inputs. The user interface can act in idle mode 30 when the keypad is active (not locked) to select diverse mobile terminal functions. The user interface comprises the elements shown in FIG. 1. The microprocessor 18 of FIG. 2 controls the user interface. Initially, a layout 30 is displayed by a mobile terminal 1 as shown in FIGS. 1 and 2, which indicates signal strength 35 from the wireless telecommunication network “D1 Telekom” 40, the battery power 45 and a dock showing the time 50 in hours and minutes. The display is on the LCD display 3. The layout 30 presents an example of the mobile terminal in idle mode 30, i.e. a state in the active mode of the keyboard 2 when the phone is activated and is awaiting an action, by pressing an alphanumeric key, receiving an incoming call or establishing an outgoing call. In the bottom of the display 3 there are two items which are denoted as “Menu” 55 and “Names” 60 under the control of two soft keys 8a and 8b shown in FIG. 1. If the user selects “Names” 60, access to a built-in phone book is achieved. If the user selects “Menu” 55, selection from different menus of selectable terminal functions may be made.
Additional functions may be performed by the user interface as described in the Assignee's U.S. patent application Ser. No. 09/506,582, filed Feb. 18, 2000, entitled “A Radiophone Provided with an Operation Key with Multiple Functionality for Handling Access to a Menu Structure” which application is incorporated herein by reference in its entirety.
The mobile terminal of FIG. 1 also has an inactive mode when the mobile terminal 1 is idle and the keypad or keyboard 3 is locked. The locking of the keypad or keyboard 3 may be accomplished by the entry of a numerical input, such as a four digit number from the keypad or keyboard 3 which prevents any mobile terminal functions from being selected by any key input including the soft keys 8, such as the placing or receiving of calls or more complicated functions, such as that described above with reference to FIG. 3. The locking of the keyboard 3 or keypad is effective to prevent accidental or unauthorized terminal functions from being activated during the idle mode when the keyboard 3 or keypad is locked and intended by the user to be inactive. Locking of keyboards or keypads is widely used in mobile terminals which do not provide keyboard covers.
FIG. 4 illustrates a display by the LCD 3 during the locked state of the keypad or keyboard 3. The displayed “locked” icon 100 visually informs the user of the idle state of the mobile terminal 1 and the locked and inactive mode of the keypad or keyboard 3. During the locked inactive mode of the keypad or keyboard 3, single key inputs to the processor 18 do not activate mobile terminal functions.
To release the “locked” state, the user of the phone inputs a command to the mobile terminal through the keypad or keyboard 3 which returns the keypad or keyboard to the active state during which normal mobile terminal functions may be selected. The command may be by the inputting from the keys of a two digit number.
Voice activated calling, which is instituted by a voice command of the user inputted to the processor 18 by the microphone 6, is currently limited to situations when the keypad or keyboard 3 is in the active mode. In this situation, the user of the mobile terminal 1 may have to take the mobile terminal 1 out of a pocket, purse or briefcase and activate the keypad or keyboard which, as stated above, typically takes two keypresses, a probable checking of the LCD display 3 to insure correctness of the action and with a long press on the menu key 55 to activate the voice caller. This degree of user action has the effect on the user, because of the required time and concentration, to make selection of voice activated calling obsolete in that it is just as easy for the user to activate the keyboard and place the call with the speed dialing feature from the keypad or keyboard 3 or browse the phone book which may be accessed by the names 60. Moreover, in situations where checking mobile terminal status is difficult, like when driving or walking, usage of the mobile terminal 1 would be enhanced if voice activated calling could be initiated by a single key press while the mobile terminal is in the idle state and the keypad or keyboard 3 is locked.
Some phones have used a dedicated key to initiate voice activated calling. This mode of calling is initiated while the phone keypad is active. Furthermore, the use of a dedicated key adds expense and complexity especially to state of the art phones which are very small.
Mobile phones are in use which use a single soft key input followed by a hard key input (e.g. #1) which locks the keypad from initiating mobile terminal functions. Thereafter, the user is only permitted, while the keypad is locked, to answer call by pressing any key including hard or soft keys.